EISA Bus Overview

EISA Bus Overview

EISA is backward compatible with ISA, but expands the ISA data bus from 16 bits to 32 bits, and provides 23 more address lines and 16 more indicator and control lines.

The EISA bus supports the following features:

all ISA transfers
bus master devices
burst-mode DMA transfers
32-bit data and address paths
peer-to-peer card communication

For detailed information on EISA-bus protocols, electrical specifications, and operation, see the standards documents ("Standards Documents" on page xxxviii). Figure 17-1 shows the high-level design of the EISA attachment in the Indigo2 architecture.

Figure 17-1 : High-Level Overview of EISA Bus in Indigo2